See through everything with a home made x-ray

[Grenadier] built his very own x-ray machine. He’s no stranger to high voltage – we’ve seen his Jacob’s Ladders and Marx generators. Surely he can handle himself with high voltage and dangerous equipment. With this portable x-ray machine, [Grenadier] has begun overloading Geiger counters. We’re just happy he knows what he’s doing.

The key component of [Grenadier]’s portable x-ray machine is the Coolidge tube, a simple vacuum tube that produces x-rays with the help of 75 kilovolts of power. The finished build looks awesome. Two meters display the milliamps and kilovolts going to the x-ray tube, and a trio of nixies display the exposure time.

Even though [Grenadier] doesn’t have x-ray film, he can see through things with a scintillation screen that fluoresces when exposed to ionizing radiation. There are two pictures of the x-ray in action – one showing the inside of a pen and the guts of a hard drive (as shown in the title pic).

The output of the x-ray was measured with a Geiger counter. [Grenadier] was able to get a hit every second or so at 50 yards, and very loud white noise at 1 foot. Check out the video of [Grenadier]’s Buildlounge laser cutter contest submission after the break.

Wow! This is really cool. I’m assuming @Grenadier you are operating this somewhat remotely! I started college studying to be a RadTech so I found this article and project super interesting. I love the details of your build the most. Great documentation on this @Grenadier.

Like someone tried to explain above it’s the long term low exposure that one would need to worry about. You’re obviously no idiot so I don’t think safety need be mentioned here. Awesome job man hope you win that laser cutter.

You can’t build it if you don’t know how. I don’t think, on average, that anyone capable of building this would have a reason to harm others with it, or be willing to go through all of this work to create a slow, prolonged, death that might be years in the making. They’d probably rather go with a more conventional means, like some form of toxin, to harm their enemies.

lool the guy who first did this was hung for witchcraft i believe… back in the 1800’s some crazy shit, and all the ppl who are all gonna be like omg this is soo dangerous…. FUCK OFF a spoon is more dangerous than a nuclear device in the right hands.

Great project. “A” for functionality and extra credit points for aesthetics.

However, with regard to the stated goal of being the “…first person in the world to DIY a portable x-ray machine and do a damn good job of it,” you’re about 52 years too late. :(

Try to find a copy of the Amateur Scientist (CL Stong, 1960) Starting with old radio tubes and moving on to a custom-blown X-ray tube, a guy by the name of Harry Simons built a functional machine strong enough to image the bones in a frozen fish, screws embedded in a block of wood, the internal parts of a light switch, and more.

The book specifically warns against applying the X-ray to one’s own body parts, but I have no doubt that the rays are of sufficient strength to make a Roentgen-style x-ray photo of a person’s hand or foot.

There is also an x-ray picture of a set of steel feeler gauges… and interesting depiction of the penetrating power of the x-rays. A 0.010-inch feeler was still partially transparent to Simons’ tube.

The power supply was an Oudin coil… no microprocessors, digital displays, or semiconductors required.

BTW, the entire Amateur Scientist series is available on CDROM. No self-respecting hacker should be without a copy. Check Google.

Unfortunately even if he does win that laser cutter he will be unable to build anything he is wanting to do. 40 watt laser cutters are unable to cut through metal, they can’t even mark it. [I have a 40 watt laser cutter]

When my mother was a child her family lived next door to a shoe store. That store and many others had an X-ray machine with the tube at the bottom, a scintillation screen at the top, and a hole to insert your foot just above the screen. The X-ray tube was powerful enough that the image of your foot bones was clearly visible on the screen in a brightly lit environment.

My mother used to like to stop in there often on her way home from school, and watch the screen while she wiggled her toes.

When she got into her 50’s, she got a bump on her foot. By time the doctors figured out that it was bone cancer, they had to remove her leg.

Another interesting case of exposing your flesh to cancer: When I was a child our family dentist would hold the X-ray film against your teeth with his thumb. As an adult I met him again and he was missing his thumb. When I asked him about it, he said most of the older dentists he knows are missing a thumb, due to repeated X-ray exposure over many years of holding X-ray in patient mouths.

Short ionizing radiation exposure is not that bad on an occasional basis. It is a high dose or a long term low dose that is the problem.

American Rrestoration had one of those machines come through in one episode. In the end they had a certified technician remove the X-Ray tube, then put some medical foot x-ray images in the viewfinders and stuck a regular CFL inside to light it up.

It was a novel marketing tool in its day, but unfortunately what we don’t know can hurt us.

here in the USA I have had dentists use my finger to hold the film in place. I’m not sure as what you are wanting to say with “These days every desent dentist haves a digital X-Ray machine of course”. I’m sure the digital Xray equipment still has to create Xray energy to produce the digitized image . No doubt plenty of good dentists still use the film Xray technology, and serve their patients well. Digital doesn’t always mean better, or safer to any large degree.

@NOLKK (why can’t I reply to your message directly?) Actually digital in this case IS safer. the digital screens are much more sensitive and the post-processing that can be done to the image can help bring out more detail and with better clarity with less of a dosage than regular film or a scintillation screen can on their own.

I do agree that the word “digital” doesn’t make things magically safer but in many cases having a completely digital sensor/imaging path is safer due to the lower equivalent dose required.

Than again “75 kilovolts of power” is a very common colloquialism. I believe the phrase was also used on the page at terravolt.org, reporter can only report what is given, and is likely to catch hell if they change thing to be technically correct, no matter how slight the change.

Beyond that hacker in general don’t want to bother about using correct terms, anymore than they want to be bothered with safety issues. ;)

A few safety points here. Common G-M counters give a count rate of ~4cps/mR/hr (these are typically only good for 1 gamma energy, not all, so your measurements are most likely 100% off or more). The inverse square law applies in radiation, thus distance is good for you. Radiation dose is photon energy dependent, low energy x-rays are emitted from these types of devices. At 50 feet, attenuation through air is significant, especially at lower energies so your close up dose is much, much, much, much higher. A GM tube is an aluminum/steel walled tube that is typically compensated for photon energy with a lead/copper mix; thus, the energy imparted to the device from an x-ray is significantly higher due to the higher attenuation of low energy x-rays to register the same number of counts. If at 50 feet you are reading a higher amount than background, do not stand closer to it because your x-ray emission is likely much higher than what your GM tube can actually read if it is even accurate in the energy range you are generating. Health limits in the US are 5rem/yr. If you are reading lots of counts at 1ft with a 4cps/mR device, then you are probably at several hundred mR/hr or higher and can reach your yearly dose within a matter of minutes. Radiation can be used safely and is fun to experiment with (I design detectors for a living), but buy some shielding materials (lead sheets) and do some basic dose calculations before you start. Also, with this experiment, you are most likely violating your state’s radiation safety laws. Depending on the state (some do not monitor x-ray equipment as closely), if your rad field is reaching the edge of your property, then you are releasing a higher dose to public which will mean a hefty fine and possibly jail time. As fun as it is for these experiments, please do it safely and talk to your state agency first. They are there to help and keep you safe, even from yourself.

Aperture is the area through which a particle has to travel for the GM tube to register – mostly what JP was saying above.

Capture ratio is the proportion of particles that have an effect. I don’t know what tube his meter is using, but for a 6993 tube the capture ratio is around 10%, so the number of photons is actually about 10x what he’s measuring.

Also, GM tubes have a “recovery time” per click. This means that if the clicks come faster than the recovery time, the tube doesn’t reset and won’t measure the particles.

This means that at high rates, the click rate can be much less than the actual count. At around 20,000 CPM (varies with different tubes) the tube will top out and register *no* clicks.

If you see measurements over 10,000 CPM, move the sensor back to reduce the rate and calculate the real rate using the inverse square law.

This brings back memories of an amazing book I found in my 8th grade library back in the early 80’s.

It had two x-ray projects. The first used a clear lightbulb. You shellac’d foil to the top of the bulb and connected it to a model-T spark coil. This producted some x-rays.

If that didn’t get your wobbly bits sufficiently tingly, they specified a number of tubes from color TV’s which had particularly high leakage. They recommended enclosing the tube in a test chamber made of 3/4″ plywood with 1/16″ of lead, as I recall.

I never made those but I did make the Arc Furnace project (a few times), which I highly recommend.

There are plenty of cheap easy to use xray sources. Any of the triode vacuum tubes used in older b&W televisions will work . In fact they were usually installed inside the television inside their own metal box with a large print label warning of the xray danger. The tubes were used for regulation of the high voltage before transistors became common. They cost about $5 for a tube.

Another tube that works is the DAC32, often found in really old car radios.
For some reason the internal structure seems particularly good at generating x-rays though you *must* put it under oil or it breaks down really quickly.

Disclaimer:- some scintillator screens are transparent to NUV as well, please take this into account when testing. I recommend using a sheet of black plastic such as photographic test film or similar to make sure what you are detecting is actually X-rays. If its intense enough to activate the screen through that ensure you are at a safe distance and VERY well shielded.